Dimethylformamide → 4-Chloro-2-[chloro(4-methylphenyl)methylidene]butanal

Participants

Reaction Conditions

Reaction Steps

390 ml of POCl3 are introduced dropwise, at a temperature of between 7° and 12° C., into a solution of 352.5 g of 4-chloro-1-(4-methylphenyl)butanone, prepared above according to Example 12a), in 450 ml of DMF. The temperature is raised gradually, in the first instance to 50° C. over 2 h and then to 75° C. over 45 min. The mixture is poured on to ice and extracted three times with ether and the organic phases are combined, washed with water and then dried and evaporated to give 387.8 g of 3-chloro-2-(2-chloroethyl)-3-(4-methylphenyl)prop-2-en-1-al in the form of an oil, which is used as such in the next step.

Provenance & Evidence